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SWL Jamming in the Cold War Era

Many of us hams of the old school started out as s.w.l.s in our youth. The international broadcast bands at the time were occupied by stations shoulder to shoulder. One of the details we encountered was jamming. We could often hear in North America that broadcasts from the B.B.C., V.O.A., Radio Liberty and many others were being jammed.

It turns out that the jamming of Western and other “undesirable” signals in the socialist countries was not a matter of the few high powered short wave transmitters that we could hear but it was a vast industry, carefully engineered and operated, with a big staff and with a huge budget.

One of the amusing details that comes up in the item at the u.r.l. below was a technique employed by China. They were broadcasting into the Soviet Union at the time. They transmitted their broadcast by running a tape backwards. To the uninitiated, it sounded as if the Chinese were jamming a short wave broadcaster themselves. The transmissions were simply ignored by the Soviet jamming system. Those interested in the Chinese transmissions recorded that “jamming” signal and then ran their own tapes backwards thereby recovering the transmitted audio in clear!

(Ed note: This article was written by fellow Coastal Ham Radio member VE7AOV. The video is very interesting but they have intentionally jammed it which I guess is for effect. It’s to bad as I couldn’t listen for anymore then 5 minutes as the content was interesting.)